Dry cell



1936- 0. K. REINHARDT ET AL 1 2,062,107

DRY CELL Filed March :50, 193.3 2 Sheets-Sheet! I III I ld!; Ii 'll!!! III! I!!! II n iv H I! I it I i INVENTORS JOHN W MEI? BY 07:70 REM/m7 1935- 0. K. REINHARDT El AL 2,

DRY CELL Filed March 30, 1933 2 Sheets-Sheet 2 FIGA 22 I, ,4,

INVENTOR- JMN w. m

ormmmw/mmr 4 Patented Nov. 24, 1936 UNITED STATES PATENT OFFICE 1 DRY CELL tion of Delaware Application March 30, 1933, Serial No. 663,476

4 Claim.

This invention relates to dry cells and more particularly to dry cells of the kind commonly known as No. 6 or 6" cells suchas are used for enunciator circuits, telephone circuits and the like, although not so limited. Heretofore, the cup shaped container of cells of this type has been closed either by'a layer of wax or sealing compound. Were a metallic closure of thin sheet steel used, electrolyte would frequently travel up the wall of the cup in the upper portion of the dry cell and attack such metallic closure and rapidly corrode it.

The present invention has for one of its obiects a metallic closure for a dry cell which is not attacked by the electrolyte. Accordingly, the clo- 15 sure is formed of zinc which is not corroded by the electrolyte.

' Another object of the invention is to secure a metallic closure of this invention to the dry cell cup. 7

It is also'an object of the invention to seal the junction of a metal closure with the rim of the cup.

'Ihe'lnvention also seeks to insulate ,a metallic closure from the central terminal or binding post thereon.

Still another object of the invention is to insulate the metallic closure from the central electrade in an effective and novel manner. v

The invention also has for its object to provide I a slghtly appearance to the top of a dry cell without adopting the more expensive expedient of 'enamelling or otherwise coloring ordecorating the top and atthe' same time to protect the metal top over its entire surface. 35 The invention also seeks a closure which is practical from'the standpoint of ease and cheapness of manufacture and durability and practicability in use. v A x In carrying the invention into effect, in accordance with one aspect, a metallic disc is carried by but insulated from the-central electrode of the cell and rests, at its periphery, on an inwardly directed shoulder on the cup wall. The closure is made of sheet zinc, which is unafiected bythe in use. A zinc closure has never. heretofore, been used due to many considerations. Superimposed upon the metal disc is a disc or annulus ofcompressible insulating material of substantially the same diameter as the metal disc. These two discs are suitably clamped to the central electrode and are secured to the wall of the cup preferably by turning over the edge of the cup inwardly onto the periphery of the insulating disc to clamp both '65 discs to the shoulder. Thus, by means of the electrolyte should any reach the surface thereof,

yielding non-metallic member .with which the metal top is clamped, a tight seal is effected.

These and other objects of the invention and the means for their attainment will be more apparent from the following detailed description,

taken in connection with the accompanying drawings illustrating various embodiments by which the invention may be realized, and in which:

Figure 1 shows a dry cell having the upper portion of the cup broken away and the closure in section;

Figure 2 shows a modification of the invention; Figure 3 shows improved means facilitating I assembly of the structure; and- Figure i: shows still another modification of F gure 1.

The invention is shown as applied to the socalled No. 6 or 6"- dry cells of the type commonly employed in enunciator circuits, telephone circuits and the like, but is applicable in whole or in its several aspects to any dry cell. A metallic cup I, conveniently of zinc, has a groove 2 rolled therein to form an inwardly directed head or shoulder 3 proximate the rim-or mouth of the cup.

The cup contains, as is usual, a suitable composition comprising a depolarizing mix (not shown) packed about a central carbon rod electrode 4, which projects upwardly, preferably, to about the transverse plane including the head 3.

' In the illustrated embodiment, a metallic binding post I is shown as protruding from the upper end of the carbon electrode 4. Obviously, the invention is not restricted to the form of conductive terminal member by which electrical conelectrode 4 and is formed with a central aper- 4 ture 9 preferably snugly receiving the binding 0st 1. p In Figure 1, the bushing 8-"! is illustrated as formed with an upwardly directed cylindrical boss in and the laterally extending portion 8 of the bushing supports a disc-like metallic closure i2. Closure i2 is formed with a central aperture II, of a diameter substantially to receive the bushing portion Ill and the edge of the aperture rests upon the laterally protruding portion 8. Thereby is the metallic closure l2, spaced from the binding post 1. Closure l2 has adiameter substantially .equal to the interior diameter of the cup' I its peripheral edge rests on the bead 3. The metallic closure i2 and bushing 8-) may thus be I readily assembled and the metallic closure I2 is conveniently centered by the boss l0. Preferably, the upper surfaces of the boss I 0 and metallic closure l2 lie in the same plane.

The bushing l8 shown in Figure 3, is disc-like in form with a downwardly depending flange l9. At its periphery, the interior diameter of the flange is substantially equal to the external diameter of the electrode 4 so that it may be readily inserted thereover and centeredthereby so that the holes for the terminal member I are in register. In Figure 4, the bushing 20 is shown without the flange.

Superimposed upon the metallic closure l2,

. there is shown, in Figures 1, 3, and 4, a disc-like member I4 of insulating material, also of substantially the same diameter as the metallic closure'and superimposed thereon. This closure I 4 is formed with a central aperture, preferably, snugly receiving the binding post I.

Superimposed upon the closure I4 of insulating material is a washer l5 preferably metallic, by which the closures and bushing are clamped to the carbon electrode. The washer I5 is conveniently of an inverted dish shape and of relatively thin metal, and the binding post 'I,in

Figures 1 and 3, is shown as formed with a flange l6 which, when the binding post is inserted in the end of the carbon electrode 4, clamps the bushing and closures together. In lieu of the flange I6, a nut 22, Figures 2 and 4, may serve a similar purpose. The pressure exerted by the flange l6 and nut 22 causes a distortion of the metallic washer l5 and forces the free edge of the washer into the insulating disc l4, thus aflord- 4 ing an efiective joint and seal at that point.

In Figures 1, 3, and 4, the freeedge I! of 'the cup I is shown as turned inwardly and downwardly over and into the closure I4 to compress the insulating material of which. the closure is formed and to clamp the closures l4 and I! to the bead 3. Furthermore, the pressure of gases,

within the cell, which occur when the'cell is in use, force the metallic disc I! and therewith the fibre disc l4 upwardly into the inturned edge so that as the pressure is increased, the seal becomes tighter.

The closure H of insulating material is, in

eflect, an annulus of sealing material which is preferably distortable and yielding whereby the joint between the metallic closure and the me: tallic cup is eil'ectively sealed. There is also pro-. vided by this construction insulating material between the washer l5 and the metallic closure l2. Obviously, the non-metallic member I 4 need not be integral, but, Figure 4 may comprise an annulus I 4' clamped by the flange II and-a bushing l4" clamped by the washer I5.-

In the modification of closure 24 is formed at its turned flange 4 standing rim 26 of the cup, 21 above the head 3. The two flanges 25 and 26 may conveniently be soldered together.

The metallic closure 24 is conveniently inverted dish shaped and rests upon a bushing 20 of any suitable kind. Superimposed upon-the periphery with an up- .closure 24 is another bushing 28 into which the edge of the washer I5 is forced by the nut 22 to seal the joint, as has been explained.

The invention is obviously not limited 'toa flange IS on the binding post I but any means is equallyapplicable which is carried thereby and which engages and forces the rim of a washer into the insulating material.

25 to be received within the up- In every instance, the metallic closure of this invention is formed from a sheet of zinc. Heretofore, in smaller cells, metallic closures have been of sheet steel. Electrolyte crawling up the walls of the cup has come into contact with the'metal closure and quickly corroded it causing a leak so that the cell has quickly deteriorated. Zinc is not attacked by the electrolytebut manufacturing difiiculties have prevented its use heretofore. With the method of securing the closure as illustrated herein, practical difliculties have been surmounted and an improved cell has resulted.

Various modifications will occur to those skilled in the art in the composition, configuration and terial being formed with a central aperture receiving the binding post, an inverted cup-shaped bushing of relatively thin metal superimposed on the closure of insulating material and formed in the cup wall near the edge thereof, a substanwith'a central aperture receiving the binding post, said binding post having means to engage the metallic bushing-to retain the bushing and discs on the electrode and force the edge of the inverted cup into the insulating material, the edge of the cup being turnuiinwardly over the closure of insulating material to clamp the closures to the bead.

2. A dry cell comprising an open top zinc cup having a groove rolled in its wall adjacent its upper end to form an inwardly extending integral annular shoulder, an electrode at the center of the cup and provided with a metallic binding post projecting therefrom out of the open end of the cup, a closure for the open end comprising two superposed discs fltted within the .open end of the cup, the inner disc being of zinc and en- Flgure 2, the metallic gaging at its periphery on the shoulder and having an opening at its center through which the binding post projects in spaced relation to the outlining edge of the opening and the other disc being of insulating material and of substantially the same diameter as the zinc disc and snugly' fitting around the binding post, the upper edge of the cup being turned-inwardly to engage the upper disc and thus secure the closure to the cup, and an insulating bushing located between the zinc closure disc and the adjacent end of the electrode.

3. In a dry cell, a metallic cup-shaped container electrode, a substantially centrally disposed electrode therein having a conductive member at its upper end, a bushing-of insulating material resting on the central electrode and formed with cup-shaped metallic washer, means carried with the conductive member to force the rim of the central aperture of a diameter greater than the.

conductive member to be spaced therefrom, a bushing of distortable insulating material superimposed on the metallic closure, said bushing of vinsulating material being formed with a central aperture receiving the conductive member, and clamping means to retain the bushings and disc on the central electrode comprising an inverted cup-shaped washer into the superimposed bushing and means to seal the rim of the clomre with the rim oi! the container.

4. In a dry cell, a metallic cup-shaped container electrode having. an inwardly directed shoulder near the upper edge thereof, acentral like metallic closure having a diameter substantially equal to the interior diameter of the cup and resting on the shoulder, an annular member of substantially yielding non-metallic material 'electrode. a binding post carried thereby a disc-\ of substantially the'same diameter as the diam- .eter of the closure superimposed thereon, means to insulate the closure from the central elecover the non-metallic annular member, a thin metal washer oi inverted dish shape encircling the binding post and bearing at its lower edge trode, the edge oi! the cup being turned inwardly v. 

